Introduction

A Phylogenetic tree or Phylogram, sometimes called the 'Tree of Life', shows the evolutionary relationships among various people that are believed to have a common ancestor. Each node with descendants represents the most recent common ancestor of the descendants, with edge lengths in our tree, corresponding to time estimates. Each node in a phylogenetic tree is called a taxonomic unit.

Although phylogenetic trees can provide evolutionary insight, they do have important limitations. Phylogenetic trees do not necessarily (and likely do not) represent actual evolutionary history. The data on which they are based is noisy and recombination and back mutations can all confound the analysis.

Analysis of Irish Type III

Presently the Irish Type III cluster has 81 haplotypes that consist of, at least, FTDNA's 67 markers. These data were taken and analysed to produce this phylogram. Dean McGee’s Y-DNA Comparison Utility http://www.mymcgee.com/tools/yutility.html was used to produce a text file containing the relative-mutations matrix data needed by the SplitTrees4 program for inferring phylogenies (evolutionary trees).

An extremely fast and simple-to-use free program, SplitsTrees4 is being used to construct the Phylogenetic tree for the Irish Type III cluster. Splitstree4 can be downloaded from www.splitstree.org  
Citation:- D. H. Huson & D. Bryant Application of Phylogenetic Networks in Evolutionary Studies, Molecular Biology and Evolution, 23(2):254-267, 2006 and http://www.math.auckland.ac.nz/~bryant/Papers/04NeighborNet.pdf  

For this exercise I have used the network form of the phylogram. (Last update - 23 May 2008).

Cautionary Note:- The tree gives some indication of how closely each of the families are related to one another but this method of time estimation is considered to only be reasonable in the longer term and relatively inaccurate in the shorter term.